Programming custom Bootloader into flash

Can someone let me know how to program a freedom board FRDM-KV11Z with a boot loader that has few edits to KBOOT v2 on target -> MKV11Z7 -> tower bootloader. I use Kiel uVision v5 and a microUSB to OpenSDA with P&E driver. I know that we could drag and drop new .srec files to replace application programs. Can we use the same technique to replace bootloader? If so, will it replace the flashloader which is already present in the flash?

I also found that KBOOT webpages are down. I have been trying to get documents and it says page not found. Do anyone know whats wrong?